Synthesis of 7-methyl-3-.BETA.-D-ribofuranosylwye, the putative structure for the hypermodified nucleoside isolated from archaebacterial transfar ribonucleic acids.
作者:Taisuke ITAYA、Masatoshi MORISUE、Motoko TAKEDA、Yukinari KUMAZAWA
DOI:10.1248/cpb.38.2656
日期:——
The Vilsmeier-Haack reaction of 3-(2, 3, 5-tri-O-acetyl-β-D-ribofuranosyl)wye (7c) followed successively by reduction with sodium borohydride and catalytic hydrogenolysis afforded the 7-methyl derivative 12c, which provided the title compound 12a on deprotection. Compound 12c was more effectively produced by direct hydrogenolysis of the 7-formyl derivative 8c, especially by use of Pearlman's catalyst. Similar treatment of 1-benzyl-7-formylwye (14) led to a better synthesis of 7-methylwye (1b), the fluorescent base isolated from Archabacterial transfer ribonucleic acids. Although hydrogenolysis of the 6-formyl compound 11 took place smoothly even over ordinary palladium on charcoal to afford 12c, this route had a bottleneck in the step of transformation of 8c into 11.Compound 12a proved to be highly sensitive to acidic hydrolysis at the glycosyl bond and the rate determined in 0.1N hydrochloric acid at 25°Cwas virtually the same as that of 3-β-D-ribofuranosylwye (7a).
通过 3-(2,3,5-三-O-乙酰基-β-D-呋喃核糖基)黑麦(7c)的 Vilsmeier-Haack 反应,然后依次用硼氢化钠还原和催化氢解,得到了 7-甲基衍生物 12c,该衍生物经脱保护后得到了标题化合物 12a。通过直接氢解 7-甲酰基衍生物 8c,特别是使用珀尔曼催化剂,可以更有效地生成化合物 12c。对 1-苄基-7-甲酰基黑麦草碱(14)进行类似处理后,可以更好地合成 7-甲基黑麦草碱(1b),这种荧光碱是从古细菌转移核糖核酸中分离出来的。化合物 12a 被证明对糖基键的酸性水解非常敏感,在 25°C 的 0.1N 盐酸中测定的速率与 3-β-D-ribofuranosylwye (7a) 几乎相同。